Mouth guard



FIG. 1 is a frontal perspective view of a mouth guard showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a right elevational view thereof; and,

FIG. 8 is a left elevational view thereof. 

The ornamental design for a mouth guard, as shown and described. 